var NumberFun = {
	/**
	 * @param num 数值
	 * @param toFixedNum 保留位数
	 * @returns {string}
	 */
	toFixedUndo : function(num,toFixedNum){
		num = num || 0;
		toFixedNum = toFixedNum || 0;
		num += '';
		if(num.indexOf('.') == -1) return Number(num).toFixed(toFixedNum);
		var pointAfterStr = num.substring(num.indexOf('.') + 1,num.indexOf('.') + toFixedNum + 1);
		pointAfterStr += '0';
		num = num.substring(0,num.indexOf('.') + 1) + pointAfterStr;
		return Number(num).toFixed(toFixedNum);
	},
	
};